The present invention is documented with various types of pivoting headrest devices, such as for use in a motor vehicle. Such headrest designs can include either or both of manual triggered or automatic release of the headrest.
U.S. Pat. No. 5,681,079 to Robinson teaches a headrest folding apparatus in which a latch release mechanism is employed permitting angular movement of the headrest from a normal use position to a dumped position. Of note, a movement coordinate mechanism is operative for causing, movement of the headrest to the dump position and in response to movement of the seatback panel to the forward fold flat position. The latch release mechanism interconnects the headrest latch to the seatback latch and is released upon the seatback latch being actuated for unlatching the seatback panel.
U.S. Pat. No. 5,826,942, to Sutton, teaches a vehicle seat assembly in which a linkage arm 36 connects a pivot 34 associated with a headrest 24 to a seatback release latch 32. The Pettersson publication 2006/0163930 and subsequent U.S. Pat. No. 7,185,950 further teaches a head restraint system with a notable cable and wheel supported arrangement for timing headrest release (see FIGS. 1 and 2).
A problem associated with the prior art concerns take up issues resulting from the inevitable slack established in the cable extending from a lower frame supporting location associated with the rotating seatback to an upper location at which it triggers release of the headrest. Absent corrective action, inevitable slack in the cable resulting from the forward rotating (or dumping) motion of the seat can cause jamming or other problems in the proper functioning of the headrest, such as during subsequent reverse rotating and retriggering to an upright design position.